Home Power Generation

Micro-generation refers to the stand alone generation of low carbon heat and/or electricity and more and more people could be looking into this option in the future to ensure reliable energy supplies to their homes and help reduce damaging emissions into the environment.

Is micro-generation, or home power generation a feasible option for the average home? What are the options available? What help can I get? Read on for the answers to these questions and an introduction to home power generation.

Overview of Technologies

Solar

Solar PV (photovoltaic) uses the sun’s energy to create electricity to run appliances and lighting. This doesn’t mean it needs to always be sunny for the electricity to be generated, as it relies simply on daylight. This option uses solar cells, usually placed on the roof, and made up of layers of semi conducting material. An electric field is created when the sun shines on the layers of the cells, causing electricity to flow. The stronger the sun, the more electricity is produced.

The pros of Solar panels or tiles include: No greenhouse gases released and low carbon dioxide emissions. They are not too obtrusive as panels can go onto the roof and solar tiles can replace roof tiles and panels covering 10-15 sq m could produce about a third of an average family’s electricity – saving on standard electricity costs.

Panels used to be heavy but the latest PV technology is light weight, so doesn’t require reinforcement of the roof. C21e solar roof tiles replace conventional tiles and are more convenient as can be installed by any roofer or competent individual.
The latest PV technology is also ideal for cities as a large proportion of buidlings are perfect for solar power as technologies now allow a number of surfaces to generate electricity eg. solar cladding, louvres. The latest PV technology replaces conventional building materials, and makes full use of space exposed to sunlight. Shading can sometimes be an issue in built up areas where not enough sunlight is getting to the panels but not in the majority of cases.

The cons include the cost – an average domestic system could cost around £4,000- £9,000 per kWp installed, with most domestic systems usually between 1.5 and 2 kWp so you are looking at between £6,000 at the lower end and £18,000 at the more expensive end. Cost will vary as tiles are more expensive than panels and integrated panels are more than standard. Planning permission may be required so you will need to check with your local authority if considering an installation.

In an effort to encourage UK households to adopt solar energy the government has introduced the Feed-in Tariff scheme which effectively pays households for every unit of energy they generate through their solar installation. The government hopes that by doing this it can meet it’s commitment to increasing the UK’s total energy from renewable sources to 15% by 2020.

Small Wind Turbines

Most people are familiar with the sight of a wind farm, but you can also generate energy at home on a smaller scale with your own wind turbine. Electricity is produced by the wind turning the turbines blades, which then turns a rotor.

At the moment wind turbines for urban locations are not really readily available, but should be developed within the next few years. The reason for this is that the turbines work best at height as wind speed is higher so space is needed – no obstructions from other buildings and trees etc.

Pros include clean power generation, cheaper than solar generation and there should be no shortage of wind, especially in coastal areas. Cons include visual impact considerations, some people see the turbines as an eyesore and they will usually require planning permission from local authority. Cost is also an issue, although cheaper than solar, wind turbines are by no means cheap. A 1kW system will cost around £3000 with larger systems in the region of 1.5kW to 6kW would cost between £4,000 – £18,000 installed. (A a typical domestic system would be 2.5 – 6 kilowatts, depending on the location and size of the home).

Biomass

Biomass, also referred to as Bioenergy or Biofuels refers to the burning of organic matter, e.g. plants, agricultural waste to make energy or heat.
It is a relatively clean energy generation method as the CO2 released during the burning is balanced out by the amount absorbed during the fuel’s production. Many different types of fuel can be used but for small-scale domestic applications of biomass wood pellets, wood chips and wood logs are usually used. Biomass is not really that practical for the average town or city household but if you are able to accommodate the equipment, biomass does have its benefits.

Biomass can be used to heat your home in two ways, either by the smaller scale stand alone stove with a 6-12 kW output fuelled by logs or pellets to heat the room or by a biomass boiler with an output of 15 kW which is connected to central heating and hot water systems. Pellets, logs or chips are used to fuel these. You will need a flue fitted and it must be the correct specifications for the fuel you are using.

Pros include, as the above two options, a cleaner, renewable fuel and cuting your energy costs by generating your own heat and hot water. There are also economic advantages the market for fuel providers is opened up. Using a local fuel source would be the most cost-effective.

The costs vary with the size and type of system but a guide is – stand alone room heaters cost around £1500 – £3000 installed. A typical 20kW (average size required for a three-bedroom semi-detached house) pellet boiler would cost around £5000 installed, including the cost of the flue and commissioning and manual log feed system of the same size would be slightly cheaper. Other considerations are sufficient space, a continual fuel supply and possible planning permission – your local authority will need to be contacted before a flue is fitted.

As there are added fuel costs with this method, it is recommended only really in areas without a gas supply.

Geothermal

This method of generation, also called ground source heat pumps utilise the natural heat of the earth. A few metres down, the soil in the UK maintains a heat of 11-12 C and by feeding a coil into the soil and transferring the heat from the ground into a building, heating and hot water can be produced. For every unit of electricity used to pump the heat, 3-4 units of heat are produced.

The advantages are that the system is cheap to run as you just pay for the pump. It is recommended for under-floor heating as this works at a lower temperature. It can be disruptive to install but for new developments it can be installed with other building works. If you are short of space it is not recommended as you will need space for a trench or borehole to accommodate the ground loop. Again, this is a good option if you are in an area where gas in unavailable.

The costs are quite high with a typical 8kW system costing between £6,400-£9,600 plus the price of connection to the distribution system. You also have to take into account the cost of running the system when it is installed.

Is it feasible?

So, after reading the above information, it may seem that generating your own energy is an impossible option, especially if you live in built up area and do not have the investment to put into it. This will be true in many domestic cases but it is not too say that this type of energy generation could not be utilised by business and organisations who have the funding. Perhaps with the introduction of grants such as the one mentioned above more people will take note of these new technologies and those who can with lead the way.